Electric vehicle, vehicle-mounted charger, and method for controlling the same

ABSTRACT

The present disclosure provides an electric vehicle, a vehicle-mounted charger and a method for controlling the same. The method includes: obtaining a first charging predetermined period Tx for controlling the H bridge in a first manner and a second charging predetermined period Ty for controlling the H bridge in a second manner when the vehicle-mounted charger starts to charge a power battery of the electric vehicle; and performing an alternate control on the H bridge in the first manner or the second manner according to the first charging predetermined period Tx and the second charging predetermined period Ty, so as to perform a temperature balanced control over the first switch tube, the second switch tube, the third switch tube and the fourth switch tube.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a national phase entry under 35 U.S.C. § 371of International Application No. PCT/CN2016/110273, filed on Dec. 16,2016, which is based on and claims priority to Chinese PatentApplication Serial No. 201510956763.8 filed on Dec. 18, 2015, allcontent of all of which is hereby incorporated by reference in itsentity.

FIELD

The present disclosure relates to the technical field of electricvehicles, in particular to a method for controlling a vehicle-mountedcharger of an electric vehicle, a vehicle-mounted charger of an electricvehicle, and an electric vehicle.

BACKGROUND

Along with the commercialization progress of electric vehicles, avehicle-mounted charger of the electric vehicles has become one ofimportant components in the electric vehicles.

There are many methods for charging the whole vehicle and fordischarging outwards from the whole vehicle via the vehicle-mountedcharger. A monophase H bridge control method is mostly adopted inrelated arts, which includes a dual-polarity control method and amono-polarity control method.

However, when the dual-polarity control method is adopted, 4 switchtubes in an H bridge are all in a high frequency ON/OFF state, resultingin higher switching loss and larger heat loss; when the mono-polaritycontrol method is adopted, although the heat loss of the switch tubesthat is generated when the dual-polarity control method is adopted canbe solved to some extent, the four switch tubes in the H bridge arecontrolled according to a fixing manner during a charging process or adischarging process of the whole vehicle, some switch tubes in the Hbridge need to be switched off with current, so that the overheatproblem of the switch tubes switched off with current is not effectivelysolved.

Therefore, no matter the dual-polarity control method or themono-polarity control method is adopted, the heating problem of theswitch tubes in the H bridge cannot be effectively solved, and theservice life of the switch tubes is affected.

SUMMARY

The present disclosure aims to solve at least one of the technicalproblems in the related art to some extent. For this purpose, a firstobjective of the present disclosure is to provide a method forcontrolling a vehicle-mounted charger of an electric vehicle, which iscapable of enabling heating of a first switch tube, a second switchtube, a third switch tube and a fourth switch tube in an H bridge to berelatively balanced, and improving a service life of the switch tubes inthe H bridge.

A second objective of the present disclosure is to provide avehicle-mounted charger of an electric vehicle. A third objective of thepresent disclosure is to provide an electric vehicle. For the abovepurpose, in one aspect of embodiments of the present disclosure, thereis provided a method for controlling a vehicle-mounted charger of anelectric vehicle. The vehicle-mounted charger includes an H bridge. TheH bridge includes a first switch tube, a second switch tube, a thirdswitch tube and a fourth switch tube. The method includes: obtaining afirst charging predetermined period Tx for controlling the H bridge in afirst manner and a second charging predetermined period Ty forcontrolling the H bridge in a second manner when the vehicle-mountedcharger starts to charge a power battery of the electric vehicle; andperforming an alternate control on the H bridge in the first manner orthe second manner according to the first charging predetermined periodTx and the second charging predetermined period Ty, so as to perform atemperature balanced control over the first switch tube, the secondswitch tube, the third switch tube and the fourth switch tube.

According to the method for controlling a vehicle-mounted charger of anelectric vehicle in embodiments of the present disclosure, when thepower battery is charged by the vehicle-mounted charger every time, thefirst charging predetermined period Tx for controlling the H bridge inthe first manner and the second charging predetermined period Ty forcontrolling the H bridge in the second manner are obtained; and thealternate control on the H bridge in the first manner or the secondmanner is performed according to the first charging predetermined periodTx and the second charging predetermined period Ty, so as to perform thetemperature balanced control over the first switch tube, the secondswitch tube, the third switch tube and the fourth switch tube, such thatthe heating of each switch tube is relatively balanced, the service lifeof the switch tubes in the H bridge is prolonged, and thus the serviceperiod is prolonged.

For the above purpose, in another aspect of embodiments of the presentdisclosure, there is provided a vehicle-mounted charger of an electricvehicle, including: an H bridge including a first switch tube, a secondswitch tube, a third switch tube and a fourth switch tube; and acontroller, configured to obtain a first charging predetermined periodTx for controlling the H bridge in a first manner and a second chargingpredetermined period Ty for controlling the H bridge in a second mannerwhen the vehicle-mounted charger starts to charge a power battery of theelectric vehicle; and to perform an alternate control on the H bridge inthe first manner or the second manner according to the first chargingpredetermined period Tx and the second charging predetermined period Ty.

According to the vehicle-mounted charger of an electric vehicle inembodiments of the present disclosure, when the power battery is chargedby the vehicle-mounted charger every time, the controller is configuredto obtain the first charging predetermined period Tx for controlling theH bridge in the first manner and the second charging predeterminedperiod Ty for controlling the H bridge in the second manner; and toperform the alternate control on the H bridge in the first manner or thesecond manner according to the first charging predetermined period Txand the second charging predetermined period Ty, so as to perform thetemperature balanced control over the first switch tube, the secondswitch tube, the third switch tube and the fourth switch tube, such thatthe heating of each switch tube is relatively balanced, the service lifeof the switch tubes in the H bridge is prolonged, and thus the serviceperiod is prolonged.

In addition, an embodiment of the present disclosure also provides anelectric vehicle, including the vehicle-mounted charger of an electricvehicle.

According to the electric vehicle in embodiments of the presentdisclosure, when the power battery is charged by the abovevehicle-mounted charger, the temperature balanced control over the firstswitch tube, the second switch tube, the third switch tube and thefourth switch tube in the H bridge can be realized, such that theheating of each switch tube is balanced, the service life of the switchtubes in the H bridge is prolonged, and thus the service period of thevehicle-mounted charger is prolonged.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit schematic diagram of a vehicle-mounted charger of anelectric vehicle of an embodiment of the present disclosure;

FIG. 2 is a circuit schematic diagram of a vehicle-mounted charger of anelectric vehicle of another embodiment of the present disclosure;

FIG. 3 is a circuit schematic diagram of a vehicle-mounted charger of anelectric vehicle of still another embodiment of the present disclosure;

FIG. 4 is a flow chart of a method for controlling a vehicle-mountedcharger of an electric vehicle of an embodiment of the presentdisclosure;

FIG. 5 is a schematic diagram of a control waveform of four switch tubeswhen an H bridge is controlled by adopting a first manner to charge apower battery according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a control waveform of four switch tubeswhen an H bridge is controlled by adopting a second manner to charge apower battery according to an embodiment of the present disclosure; and

FIG. 7 is a flow chart of a method for controlling a vehicle-mountedcharger of an electric vehicle of an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

The embodiments of the present disclosure are described in detail,examples of the embodiments are shown in the drawings, wherein, the sameor similar numbers represent same or similar elements or elements havingthe same or similar functions from beginning to end. The embodimentsdescribed with reference to the drawings are exemplary, and aim toexplain the present disclosure rather than understood as a limitation tothe present disclosure.

The method for controlling a vehicle-mounted charger of an electricvehicle, a vehicle-mounted charger of an electric vehicle, and anelectric vehicle with the vehicle-mounted charger, provided inembodiments of the present disclosure, are described with reference tothe drawings as follows.

FIGS. 1 to 3 show a connecting manner of a vehicle-mounted charger of anelectric vehicle according to an embodiment of the present disclosure.As shown in FIGS. 1 to 3, the vehicle-mounted charger of an electricvehicle according to embodiments of the present disclosure includes an Hbridge. The H bridge includes a first switch tube T1, a second switchtube T2, a third switch tube T3 and a fourth switch tube T4. Thevehicle-mounted charger of an electric vehicle as shown in FIG. 1includes a first inductor L1 and a second inductor L2, in which a firstend of the first inductor L1 is connected to one end of a load or ananode end of an alternating current power grid AC, and a first end ofthe second inductor L2 is connected to the other end of the load or acathode end of the alternating current power grid AC, and a second endof the first inductor L1 and a second end of the second inductor L2 areconnected to the H bridge. The vehicle-mounted charger of an electricvehicle as shown in FIG. 2 merely includes an inductor, for example, theinductor L1, in which a first end of the first inductor L1 is connectedto one end of a load or an anode end of an alternating current powergrid AC, and a second end of the first inductor L1 is connected to the Hbridge. The vehicle-mounted charger of an electric vehicle as shown inFIG. 3 merely includes an inductor, for example, the first inductor L1,in which a first end of the first inductor L1 is connected to the otherend of the load or a cathode end of the alternating current power gridAC, and a second end of the first inductor L1 is connected to the Hbridge.

FIG. 4 is a flow chart of a method for controlling a vehicle-mountedcharger of an electric vehicle according to an embodiment of the presentdisclosure. As shown in FIG. 4, the method for controlling avehicle-mounted charger of an electric vehicle in an embodiment of thepresent disclosure includes followings.

At step S1, a first charging predetermined period Tx for controlling theH bridge in a first manner and a second charging predetermined period Tyfor controlling the H bridge in a second manner are obtained when thevehicle-mounted charger starts to charge a power battery of the electricvehicle.

According to an embodiment of the present disclosure, as shown in FIG.5, if the H bridge is controlled in the first manner A to charge thepower battery, and when a power grid transient voltage value supplied tothe vehicle-mounted charger is larger than 0, the first switch tube T1is controlled to be ON, the second switch tube T2 is controlled to beOFF, and the third switch tube T3 and the fourth switch tube T4 arecontrolled to be ON and OFF complementarily and alternately. When thethird switch tube T3 and the fourth switch tube T4 are controlled to beON and OFF alternately and complementarily, the PWM waveform of thethird switch tube T3 and the PWM waveform of the fourth switch tube T4are controlled to be complementary with each other, and a duty ratio ofthe PWM waveform of the third switch tube T3 is controlled from large tosmall and then to large, and a duty ratio of the PWM waveform of thefourth switch tube T4 is controlled from small to large and then tosmall; when the power grid transient voltage value supplied to thevehicle-mounted charger is smaller than 0, the third switch tube T3 iscontrolled to be ON, the fourth switch tube T4 is controlled to be OFF,and the first switch tube T1 and the second switch tube T2 arecontrolled to be ON and OFF complementarily and alternately. When thefirst switch tube T1 and the second switch tube T2 are controlled to beON and OFF alternately and complementarily, the PWM waveform of thefirst switch tube T1 and the PWM waveform of the second switch tube T2are controlled to be complementary with each other, and a duty ratio ofthe PWM waveform of the first switch tube T1 is controlled from large tosmall and then to large, and a duty ratio of the PWM waveform of thesecond switch tube T2 is controlled from small to large and then tosmall.

According to an embodiment of the present disclosure, as shown in FIG.6, if the H bridge is controlled in the second manner B to charge thepower battery, and when a power grid transient voltage value supplied tothe vehicle-mounted charger is larger than 0, the second switch tube T2is controlled to be ON, the first switch tube T1 is controlled to beOFF, and the third switch tube T3 and the fourth switch tube T4 arecontrolled to be ON and OFF complementarily and alternately. When thethird switch tube T3 and the fourth switch tube T4 are controlled to beON and OFF alternately and complementarily, the PWM waveform of thethird switch tube T3 and the PWM waveform of the fourth switch tube T4are controlled to be complementary with each other, and a duty ratio ofthe PWM waveform of the third switch tube T3 is controlled from small tolarge and then to small, and a duty ratio of the PWM waveform of thefourth switch tube T4 is controlled from large to small and then tolarge; when the power grid transient voltage value supplied to thevehicle-mounted charger is smaller than 0, the fourth switch tube T4 iscontrolled to be ON, the third switch tube T3 is controlled to be OFF,and the first switch tube T1 and the second switch tube T2 arecontrolled to be ON and OFF complementarily and alternately. When thefirst switch tube T1 and the second switch tube T2 are controlled to beON and OFF alternately and complementarily, the PWM waveform of thefirst switch tube T1 and the PWM waveform of the second switch tube T2are controlled to be complementary with each other, and a duty ratio ofthe PWM waveform of the first switch tube T1 is controlled from small tolarge and then to small, and a duty ratio of the PWM waveform of thesecond switch tube T2 is controlled from large to small and then tolarge.

At step S2, an alternate control on the H bridge in the first manner orthe second manner is performed according to the first chargingpredetermined period Tx and the second charging predetermined period Ty,so as to perform a temperature balanced control over the first switchtube, the second switch tube, the third switch tube and the fourthswitch tube.

In an embodiment of the present disclosure, the first chargingpredetermined period Tx and the second charging predetermined period Tyare preset for each charging cycle of a charging process of the powerbattery.

In the process of charging the power battery by the vehicle-mountedcharger, if the H bridge is only controlled by adopting the first mannerA, when the power grid transient voltage value is larger than 0, thefirst switch tube T1 is kept ON always, the second switch tube T2 iskept OFF always, and the third switch tube T3 and fourth switch tube T4are ON and OFF alternately and complementarily, and the inductor in thevehicle-mounted charger is charged when the third switch tube T3 is ONand the fourth switch tube T4 is OFF, and discharges when the thirdswitch tube T3 is OFF and the fourth switch tube T4 is ON; when thepower grid transient voltage value is smaller than 0, the third switchtube T3 is kept ON always, the fourth switch tube T4 is kept OFF always,and the first switch tube T1 and second switch tube T2 are ON and OFFalternately and complementarily, and the inductor in the vehicle-mountedcharger is charged when the first switch tube T1 is ON and the secondswitch tube T2 is OFF, and discharges when the first switch tube T1 isOFF and the second switch tube T2 is ON. Since the inductor is chargedwhen the first switch tube T1 and the third switch tube T3 are ON, an ONduty ratio is larger, therefore, the first switch tube T1 and the thirdswitch tube T3 are overheated.

Similarly, in the process of charging the power battery by thevehicle-mounted charger, if the H bridge is only controlled by adoptingthe second manner B, when the power grid transient voltage value islarger than 0, the first switch tube T1 is kept OFF always, the secondswitch tube T2 is kept ON always, and the third switch tube T3 and thefourth switch tube T4 are ON and OFF alternately and complementarily,and the inductor in the vehicle-mounted charger is charged when thefourth switch tube T4 is ON and the third switch tube T3 is OFF, anddischarges when the fourth switch tube T4 is OFF and the third switchtube T3 is ON; when the power grid transient voltage value is smallerthan 0, the fourth switch tube T4 is kept ON always, the third switchtube T3 is kept OFF always, and the first switch tube T1 and secondswitch tube T2 are ON and OFF alternately and complementarily, and theinductor in the vehicle-mounted charger is charged when the secondswitch tube T2 is ON and the first switch tube T1 is OFF, and dischargeswhen the second switch tube T2 is OFF and the first switch tube T1 isON. Since the inductor is charged when the second tube T2 and the fourthtube T4 are ON, an ON duty ratio is larger, therefore, the second switchtube T2 and the fourth switch tube T4 are overheated.

Therefore, in an embodiment of the present disclosure, when thevehicle-mounted charger charges the power battery every time, the firstcharging predetermined period Tx and the second charging predeterminedperiod Ty is preset, and then in the process of charging the powerbattery, firstly the H bridge can be controlled by selecting the firstmanner A to enable the vehicle-mounted charger to charge the powerbattery till the period that the H bridge is controlled in the firstmanner A reaches the first charging predetermined period Tx, then the Hbridge is switched to be controlled by adopting the second manner B tillthe period that the H bridge is controlled in the second manner Breaches the second charging predetermined period Ty, thereby finishingone charging cycle (i.e., the period of one charging cycle equals toTx+Ty); then the H bridge is switched to be controlled by adopting thefirst manner A to enable the vehicle-mounted charger to charge the powerbattery till the period that the H bridge is controlled by adopting thefirst manner A reaches the first charging predetermined period Tx, thenthe H bridge is switched to be controlled by adopting the second mannerB to enable the vehicle-mounted charger to charge the power battery tillthe period that the H bridge is controlled by adopting the second mannerB reaches the second charging predetermined period Ty, . . . , and thelike, thereby realizing the alternative control over the H bridge, andfurther performing the temperature balanced control over the firstswitch tube, the second switch tube, the third switch tube and thefourth switch tube. Or, in the process of charging the power battery,firstly the H bridge can be controlled by selecting the second manner Bto enable the vehicle-mounted charger to charge the power battery tillthe period that the H bridge is controlled in the second manner Breaches the second charging predetermined period Ty, then the H bridgeis switched to be controlled by adopting the first manner A till theperiod that the H bridge is controlled in the first manner A reaches thefirst charging predetermined period Tx, thereby finishing one chargingcycle (i.e., the period of one charging cycle equals to Tx+Ty); then theH bridge is switched to be controlled by adopting the second manner B toenable the vehicle-mounted charger to charge the power battery till theperiod that the H bridge is controlled by adopting the second manner Breaches the second charging predetermined period Ty, then the H bridgeis switched to be controlled by adopting the first manner A to enablethe vehicle-mounted charger to charge the power battery till the periodthat the H bridge is controlled by adopting the first manner A reachesthe first charging predetermined period Tx, . . . , and the like,thereby realizing the alternative control over the H bridge, and furtherperforming the temperature balanced control over the first switch tube,the second switch tube, the third switch tube and the fourth switchtube.

In other words, at step S2, the alternate control is performed on the Hbridge according to the first charging predetermined period Tx and thesecond charging predetermined period Ty when the power battery ischarged by the vehicle-mounted charger includes: when a period ofcontrolling the H bridge in the first manner reaches the first chargingpredetermined period Tx, controlling the H bridge in the second mannertill a period of controlling the H bridge in the second manner reachesthe second charging predetermined period Ty; or when a period ofcontrolling the H bridge in the second manner reaches the secondcharging predetermined period Ty, controlling the H bridge in the firstmanner till a period of controlling the H bridge in the first mannerreaches the first charging predetermined period Tx.

In one embodiment of the present disclosure, the first chargingpredetermined period Tx that the H bridge is controlled in the firstmanner A is equal to the second charging predetermined period Ty thatthe H bridge is controlled in the second manner B, thereby preciselycontrolling heating of the first switch tube, the second switch tube,the third switch tube and the fourth switch tube to be relativelybalanced.

According to one embodiment of the present disclosure, as shown in FIG.7, the method for controlling a vehicle-mounted charger of an electricvehicle includes the followings.

At step S501, a charging wave is opened, i.e., when the vehicle-mountedcharger charges the power battery, a control waveform needs to be outputto control the switch tubes in the H bridge. At step S502, a firstcharging predetermined period Tx and a second charging predeterminedperiod Ty are set.

At step S503, the first manner A is selected to control the H bridge.

At step S504, it is judged whether a period of controlling the H bridgein the first manner A reaches the first charging predetermined periodTx, then step S505 is executed if yes and step S503 is executed if not.

At step S505, it is judged whether the charging process is over, thenstep S509 is executed if yes and step S505 is executed if not.

At step S506, the second manner B is selected to control the H bridge.

At step S507, it is judged whether a period of controlling the H bridgein the second manner B reaches the second charging predetermined periodTy, then step S508 is executed if yes and step S506 is executed if not.

At step S508, it is judged whether the charging process is over, thenstep S509 is executed if yes and step S503 is executed if not.

At step S509, the charging process is over.

Therefore, according to the method for controlling a vehicle-mountedcharger of an electric vehicle, in the process that the vehicle-mountedcharger charges the power battery every time, the heating of the firstswitch tube, the second switch tube, the third switch tube and thefourth switch tube is enabled to be relative balanced, and the servicelife of the vehicle-mounted charger is prolonged.

According to the method for controlling a vehicle-mounted charger of anelectric vehicle in embodiments of the present disclosure, when thepower battery is charged by the vehicle-mounted charger every time, thefirst charging predetermined period Tx for controlling the H bridge inthe first manner and the second charging predetermined period Ty forcontrolling the H bridge in the second manner are preset; and thealternate control on the H bridge in the first manner or the secondmanner is performed according to the first charging predetermined periodTx and the second charging predetermined period Ty, so as to perform thetemperature balanced control over the first switch tube, the secondswitch tube, the third switch tube and the fourth switch tube, such thatthe heating of each switch tube is relatively balanced, the service lifeof the switch tubes in the H bridge is prolonged, and thus the serviceperiod is prolonged.

As shown in FIGS. 1 to 3, a vehicle-mounted charger according toembodiments of the present disclosure includes an H bridge and acontroller such as an MCU (Micro Control Unit). The H bridge includes afirst switch tube T1, a second switch tube T2, a third switch tube T3and a fourth switch tube T4. The controller is configured to obtain afirst charging predetermined period Tx for controlling the H bridge in afirst manner and a second charging predetermined period Ty forcontrolling the H bridge in a second manner when the vehicle-mountedcharger starts to charge the power; and to perform an alternate controlon the H bridge in the first manner or the second manner according tothe first charging predetermined period Tx and the second chargingpredetermined period Ty, so as to perform a temperature balanced controlover the first switch tube T1, the second switch tube T2, the thirdswitch tube T3 and the fourth switch tube T4.

In an embodiment, the controller is configured to perform the alternatecontrol on the H bridge according to the first charging predeterminedperiod Tx and the second charging predetermined period Ty when the powerbattery is charged by the vehicle-mounted charger by steps of: when aperiod of controlling the H bridge in the first manner reaches the firstcharging predetermined period Tx, controlling the H bridge in the secondmanner till a period of controlling the H bridge in the second mannerreaches the second charging predetermined period Ty; or when a period ofcontrolling the H bridge in the second manner reaches the secondcharging predetermined period Ty, controlling the H bridge in the firstmanner till a period of controlling the H bridge in the first mannerreaches the first charging predetermined period Tx.

That is to say, when the vehicle-mounted charger charges the powerbattery every time, the first charging predetermined period Tx and thesecond charging predetermined period Ty are preset, and then in theprocess of charging the power battery, firstly the H bridge can becontrolled by selecting the first manner A to enable the vehicle-mountedcharger to charge the power battery till the period that the H bridge iscontrolled in the first manner A reaches the first chargingpredetermined period Tx, then the H bridge is switched to be controlledby adopting the second manner B till the period that the H bridge iscontrolled in the second manner B reaches Ty, thereby finishing onecharging cycle (i.e., the period of one charging cycle equals to Tx+Ty);then the H bridge is switched to be controlled by adopting the firstmanner A to enable the vehicle-mounted charger to charge the powerbattery till the period that the H bridge is controlled by adopting thefirst manner A reaches the first charging predetermined period Tx, thenthe H bridge is switched to be controlled by adopting the second mannerB to enable the vehicle-mounted charger to charge the power battery tillthe period that the H bridge is controlled by adopting the second mannerB reaches the second charging predetermined period Ty, . . . , and thelike, thereby realizing the alternative control over the H bridge, andfurther performing the temperature balanced control over the firstswitch tube, the second switch tube, the third switch tube and thefourth switch tube. Or, in the process of charging the power battery,firstly the H bridge can be controlled by selecting the second manner Bto enable the vehicle-mounted charger to charge the power battery tillthe period that the H bridge is controlled in the second manner Breaches the second charging predetermined period Ty, then the H bridgeis switched to be controlled by adopting the first manner A till theperiod that the H bridge is controlled in the first manner A reaches thefirst charging predetermined period Tx, thereby finishing one chargingcycle (i.e., the period of one charging cycle equals to Tx+Ty); then theH bridge is switched to be controlled by adopting the second manner B toenable the vehicle-mounted charger to charge the power battery till theperiod that the H bridge is controlled by adopting the second manner Breaches the second charging predetermined period Ty, then the H bridgeis switched to be controlled by adopting the first manner A to enablethe vehicle-mounted charger to charge the power battery till the periodthat the H bridge is controlled by adopting the first manner A reachesthe first charging predetermined period Tx, . . . , and the like,thereby realizing the alternative control over the H bridge, and furtherperforming the temperature balanced control over the first switch tube,the second switch tube, the third switch tube and the fourth switchtube.

In an embodiment of the present disclosure, the first chargingpredetermined period Tx that the H bridge is controlled in the firstmanner equals to the second charging predetermined period Ty that the Hbridge is controlled in the second manner.

According to an embodiment of the present disclosure, if the controlleris configured to control the H bridge in the first manner A to chargethe power battery, when a power grid transient voltage value supplied tothe vehicle-mounted charger is larger than 0, the first switch tube T1is controlled to be ON, the second switch tube T2 is controlled to beOFF, and the third switch tube T3 and the fourth switch tube T4 arecontrolled to be ON and OFF complementarily and alternately. When thethird switch tube T3 and the fourth switch tube T4 are controlled to beON and OFF alternately and complementarily, the PWM waveform of thethird switch tube T3 and the PWM waveform of the fourth switch tube T4are controlled to be complementary with each other, and a duty ratio ofthe PWM waveform of the third switch tube T3 is controlled from large tosmall and then to large, and a duty ratio of the PWM waveform of thefourth switch tube T4 is controlled from small to large and then tosmall; when the power grid transient voltage value supplied to thevehicle-mounted charger is smaller than 0, the third switch tube T3 iscontrolled to be ON, the fourth switch tube T4 is controlled to be OFF,and the first switch tube T1 and the second switch tube T2 arecontrolled to be ON and OFF complementarily and alternately. When thefirst switch tube T1 and the second switch tube T2 are controlled to beON and OFF alternately and complementarily, the PWM waveform of thefirst switch tube T1 and the PWM waveform of the second switch tube T2are controlled to be complementary with each other, and a duty ratio ofthe PWM waveform of the first switch tube T1 is controlled from large tosmall and then to large, and a duty ratio of the PWM waveform of thesecond switch tube T2 is controlled from small to large and then tosmall.

According to an embodiment of the present disclosure, if the controlleris configured to control the H bridge in the second manner B to chargethe power battery, when a power grid transient voltage supplied to thevehicle-mounted charger is larger than 0, the second switch tube T2 iscontrolled to be ON, the first switch tube T1 is controlled to be OFF,and the third switch tube T3 and the fourth switch tube T4 arecontrolled to be ON and OFF complementarily and alternately. When thethird switch tube T3 and the fourth switch tube T4 are controlled to beON and OFF alternately and complementarily, the PWM waveform of thethird switch tube T3 and the PWM waveform of the fourth switch tube T4are controlled to be complementary with each other, and a duty ratio ofthe PWM waveform of the third switch tube T3 is controlled from small tolarge and then to small, and a duty ratio of the PWM waveform of thefourth switch tube T4 is controlled from large to small and then tolarge; when the power grid transient voltage value supplied to thevehicle-mounted charger is smaller than 0, the fourth switch tube T4 iscontrolled to be ON, the third switch tube T3 is controlled to be OFF,and the first switch tube T1 and the second switch tube T2 arecontrolled to be ON and OFF complementarily and alternately. When thefirst switch tube T1 and the second switch tube T2 are controlled to beON and OFF alternately and complementarily, the PWM waveform of thefirst switch tube T1 and the PWM waveform of the second switch tube T2are controlled to be complementary with each other, and a duty ratio ofthe PWM waveform of the first switch tube T1 is controlled from small tolarge and then to small, and a duty ratio of the PWM waveform of thesecond switch tube T2 is controlled from large to small and then tolarge.

In an embodiment of the present disclosure, as shown in FIG. 1 or FIG. 2or FIG. 3, the first switch tube T1, the second switch tube T2, thethird switch tube T3 and the fourth switch tube T4 are all IGBTs(Insulated Gate Bipolar Transistors), certainly, in other embodiments ofthe present disclosure, the first switch tube T1, the second switch tubeT2, the third switch tube T3 and the fourth switch tube T4 can also beMOSs (Metal Oxide Semiconductors).

In an embodiment, the first charging predetermined period Tx and thesecond charging predetermined period Ty are preset for each chargingcycle of a charging process of the power battery, so as to performtemperature balanced control over the first switch tube, the secondswitch tube, the third switch tube and the fourth switch tube.

According to the vehicle-mounted charger of an electric vehicle inembodiments of the present disclosure, when the power battery is chargedby the vehicle-mounted charger every time, the controller is configuredto obtain the first charging predetermined period Tx for controlling theH bridge in the first manner and the second charging predeterminedperiod Ty for controlling the H bridge in the second manner; and toperform the alternate control on the H bridge in the first manner or thesecond manner according to the first charging predetermined period Txand the second charging predetermined period Ty, so as to performtemperature balanced control over the first switch tube, the secondswitch tube, the third switch tube and the fourth switch tube, such thatthe heating of each switch tube is relatively balanced, the service lifeof the switch tubes in the H bridge is prolonged, and thus the serviceperiod is prolonged.

In addition, embodiments of the present disclosure also provide anelectric vehicle, including the above vehicle-mounted charger of anelectric vehicle.

According to the electric vehicle in embodiments of the presentdisclosure, when the power battery is charged by the abovevehicle-mounted charger, the temperature balanced control over the firstswitch tube, the second switch tube, the third switch tube and thefourth switch tube in the H bridge can be realized, such that theheating of each switch tube is balanced, the service life of the switchtubes in the H bridge is prolonged, and thus the service period of thevehicle-mounted charger is prolonged.

In the description of the present disclosure, it is understandable thatthe directions of position relations indicated by the terms “center”,“longitudinal”, “transverse”, “length”, “width”, “thickness”, “upper”,“lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”,“top”, “bottom”, “inner”, “outer”, “clockwise”, “counterclockwise”,“axial”, “radial” and “peripheral” are based on the directions orposition relations as shown in the drawings, are merely convenient fordescribing the present disclosure and simplifying the description ratherthan indicating or implying the fact that devices or elements must havespecific directions, or configured or operated in specific directions,and thus cannot understood as a limitation to the present disclosure.

In addition, the terms “first” and “second” merely aim to describerather than being understood as indication or implication of relativeimportance or impliedly indicating a number of the indicated technicalfeatures. Therefore, the characteristics defined by “first” and “second”can clearly or impliedly comprise at least one such characteristic. Inthe description of the present disclosure, “more” means at least two,for example, two, three, etc., unless otherwise clearly specificallydefined.

In the present disclosure, unless otherwise clearly specified anddefined, the terms “mounted”, “jointed”, “connected”, “fixed”, etc.,should be generalized understood, for example, the “connected” can befixedly connected, or detachably connected, or integrated, can bemechanically connected or electrically connected, can also be directlyconnected or connected by an intermediate medium, and can also beinternally communicated of two elements, or interacted of two elements,unless otherwise clearly defined. Those ordinary skilled in the art canunderstand the specific meaning of the terms in the present disclosureaccording to specific conditions.

In the present disclosure, unless otherwise clearly specified anddefined, the case that a first characteristic is “on” or “under” asecond characteristic can be the case that the first characteristic andthe second characteristic are in direct contact, or in indirect contactby an intermediate medium. Besides, the case that the firstcharacteristic is “on”, “above” and “over” the second characteristic canbe the case that the first characteristic is right or obliquely abovethe second characteristic, or only represents that the horizontal heightof the first characteristic is higher than that of the secondcharacteristic. The case that the first characteristic is “under”,“below” and “beneath” the second characteristic can be the case that thefirst characteristic is right or obliquely below the secondcharacteristic, or only represents that the horizontal height of thefirst characteristic is lower than that of the second characteristic.

In the description of the specification, the description of thereference terms “one embodiment”, “some embodiments”, “examples”,“specific examples” or “some examples” refers to the fact that thespecific characteristic, structure, material or feature described incombination with the embodiment or example is contained in the at leastone embodiment or example of the present disclosure. In the presentspecification, and the schematic expression of the above termsunnecessarily aims at the same embodiment or example. In addition, thedescribed specific characteristic, structure, material or feature can becombined in a proper manner in any one or more embodiments or examples.Besides, in the case without mutual contradiction, those skilled in theart can integrate or combine different embodiments or examples or thecharacteristics of different embodiments or examples described in thepresent specification.

Although the embodiments of the present disclosure have been shown anddescribed as above, it is understandable that those ordinary skilled inthe art can change, modify, substitute and transform the aboveembodiments in a scope of the present disclosure.

What is claimed is:
 1. A method for controlling a vehicle-mountedcharger of an electric vehicle, wherein the vehicle-mounted chargercomprises an H bridge, and the H bridge comprises a first switchtransistor, a second switch transistor, a third switch transistor and afourth switch transistor, the method comprising: obtaining a firstpredetermined charging time (Tx) for controlling the H bridge in a firstmanner and a second predetermined charging time (Ty) for controlling theH bridge in a second manner when the vehicle-mounted charger starts tocharge a power battery of the electric vehicle; and performing analternate control on the H bridge in the first manner or the secondmanner according to the first predetermined charging time (Tx) and thesecond predetermined charging time (Ty), so as to perform atemperature-balanced control over the first switch transistor, thesecond switch transistor, the third switch transistor and the fourthswitch transistor.
 2. The method according to claim 1, wherein the firstpredetermined charging time (Tx) and the second predetermined chargingtime (Ty) are preset for each charging cycle of a charging process ofthe power battery.
 3. The method according to claim 1 or 2, whereinperforming an alternate control on the H bridge in the first manner orthe second manner according to the first predetermined charging time(Tx) and the second predetermined charging time (Ty) comprises:controlling the H bridge in the first manner until a time of controllingthe H bridge in the first manner reaches the first predeterminedcharging time (Tx) and controlling the H bridge in the second manneruntil a time of controlling the H bridge in the second manner reachesthe second predetermined charging time (Ty); or controlling the H bridgein the second manner until a time of controlling the H bridge in thesecond manner reaches the second predetermined charging time (Ty) andcontrolling the H bridge in the first manner until a time of controllingthe H bridge in the first manner reaches the first predeterminedcharging time (Tx).
 4. The method according to claim 1, whereincontrolling the H bridge in the first manner comprises: when a powergrid transient voltage value supplied to the vehicle-mounted charger islarger than 0, controlling the first switch transistor to be ON,controlling the second switch transistor to be OFF, and controlling thethird switch transistor and the fourth switch transistor to be ON andOFF alternately and complementarily; and when the power grid transientvoltage value supplied to the vehicle-mounted charger is smaller than 0,controlling the third switch transistor to be ON, controlling the fourthswitch transistor to be OFF, and controlling the first switch transistorand the second switch transistor to be ON and OFF alternately andcomplementarily.
 5. The method according to claim 1, wherein controllingthe H bridge in the second manner, when a power grid transient voltagevalue supplied to the vehicle-mounted charger is larger than 0,controlling the second switch transistor to be ON, controlling the firstswitch transistor to be OFF, and controlling the third switch transistorand the fourth switch transistor to be ON and OFF alternately andcomplementarily; and when the power grid transient voltage valuesupplied to the vehicle-mounted charger is smaller than 0, controllingthe fourth switch transistor to be ON, controlling the third switchtransistor to be OFF, and controlling the first switch transistor andthe second switch transistor to be ON and OFF alternately andcomplementarily.
 6. The method according to claim 5, wherein the firstpredetermined charging time (Tx) is equal to the second predeterminedcharging time (Ty).
 7. A vehicle-mounted charger of an electric vehicle,comprising: an H bridge, comprising a first switch transistor, a secondswitch transistor, a third switch transistor and a fourth switchtransistor; and a controller, configured to obtain a first predeterminedcharging time (Tx) for controlling the H bridge in a first manner and asecond predetermined charging time (Ty) for controlling the H bridge ina second manner when the vehicle-mounted charger starts to charge apower battery of the electric vehicle; and to perform an alternatecontrol on the H bridge in the first manner or the second manneraccording to the first predetermined charging time (Tx) and the secondpredetermined charging time (Ty), so as to perform atemperature-balanced control over the first switch transistor, thesecond switch transistor, the third switch transistor and the fourthswitch transistor.
 8. The vehicle-mounted charger according to claim 7,wherein the first predetermined charging time (Tx) and the secondpredetermined charging time (Ty) are preset for each charging cycle of acharging process of the power battery.
 9. The vehicle-mounted chargeraccording to claim 7, wherein the controller is configured to: controlthe H bridge in the first manner until a time of controlling the Hbridge in the first manner reaches the first predetermined charging time(Tx) and control the H bridge in the second manner until a time ofcontrolling the H bridge in the second manner reaches the secondpredetermined charging time (Ty); or control the H bridge in the secondmanner until a time of controlling the H bridge in the second mannerreaches the second predetermined charging time (Ty) and control the Hbridge in the first manner until a time of controlling the H bridge inthe first manner reaches the first predetermined charging time (Tx). 10.The vehicle-mounted charger according to claim 7, wherein the controlleris further configured to: control the first switch transistor to be ON,the second switch transistor to be OFF and the third switch transistorand the fourth switch transistor to be ON and OFF alternately andcomplementarily when a power grid transient voltage value supplied tothe vehicle-mounted charger is larger than 0; and control the thirdswitch transistor to be ON, the fourth switch transistor to be OFF, andthe first switch transistor and the second switch transistor to be ONand OFF alternately and complementarily when the power grid transientvoltage value supplied to the vehicle-mounted charger is smaller than 0.11. The vehicle-mounted charger according to claim 7, wherein thecontroller is further configured to: control the second switchtransistor to be ON, the first switch transistor to be OFF, and thethird switch transistor and the fourth switch transistor to be ON andOFF alternately and complementarily when a power grid transient voltagevalue supplied to the vehicle-mounted charger is larger than 0; controlthe fourth switch transistor to be ON, the third switch transistor to beOFF, and the first switch transistor and the second switch transistor tobe ON and OFF alternately and complementarily when the power gridtransient voltage value supplied to the vehicle-mounted charger issmaller than
 0. 12. The vehicle-mounted charger according to claim 7,wherein the first predetermined charging time (Tx) is equal to thesecond predetermined charging time (Ty).
 13. An electric vehicle,comprising: a vehicle-mounted charger, wherein the vehicle-mountedcharger comprises: an H bridge, comprising a first switch transistor, asecond switch transistor, a third switch transistor and a fourth switchtransistor; and a controller, configured to obtain a first predeterminedcharging time (Tx) for controlling the H bridge in a first manner and asecond predetermined charging time (Ty) for controlling the H bridge ina second manner when the vehicle-mounted charger starts to charge apower battery of the electric vehicle; and to perform an alternatecontrol on the H bridge in the first manner or the second manneraccording to the first predetermined charging time (Tx) and the secondpredetermined charging time (Ty), so as to perform atemperature-balanced control over the first switch transistor, thesecond switch transistor, the third switch transistor and the fourthswitch transistor.
 14. The electric vehicle according to claim 13,wherein the first predetermined charging time (Tx) and the secondpredetermined charging time (Ty) are preset for each charging cycle of acharging process of the power battery.
 15. The electric vehicleaccording to claim 13, wherein the controller is configured to: controlthe H bridge in the first manner until a time of controlling the Hbridge in the first manner reaches the first predetermined charging time(Tx) and control the H bridge in the second manner until a time ofcontrolling the H bridge in the second manner reaches the secondpredetermined charging time (Ty); or control the H bridge in the secondmanner until a time of controlling the H bridge in the second mannerreaches the second predetermined charging time (Ty) and control the Hbridge in the first manner until a time of controlling the H bridge inthe first manner reaches the first predetermined charging time (Tx).